U.S. Pat. No. 5,532,415 discloses R(+)-N-propargyl-1-aminoindan, its preparation, and various pharmaceutically acceptable salts thereof. U.S. Pat. No. 6,126,968 discloses pharmaceutical compositions comprising R(+)PAI. R(+)PAI and salts thereof have been shown to be selective inhibitors of MAO-B, useful in treating Parkinson's disease and various other conditions.
While not previously identified as a problem for R(+)PAI, a drug substance may be composed of particles which are an impediment, e.g. due to size and shape, to a homogeneous distribution of the drug substance in a tablet blend. If such a drug substance, without further processing, were used in tablet manufacture, the tablets so produced would lack content uniformity and not possess acceptable drug content (e.g., U.S. Pat. No. 5,622,720). Poor content uniformity has been shown to cause a marked decrease in bioavailability. Poor content uniformity can also cause toxicity, if the amount of drug substance is too high.
Due to the increased awareness of bioavailability and safety, compendial authorities such as the United States Pharmacopoeia (USP) have implemented a multi-stage content uniformity test, which includes 1) assaying ten tablets to ensure that the relative standard deviation (RSD) of active content is less than or equal to 6.0% and no value is outside 85-115%; and 2) assaying twenty more tablets to ensure that the RSD for all thirty tablets is less than or equal to 7.8%, no more than one value is outside 85-115% and no value is outside 75-125% of stated content.